Slide-fastener slider with locking pawl



Aug. 4, 1970 R. AMBROS ET AL 3,522,638

SLIDE-FASTENER SLIDER WITH LOCKING PAWL Filed Sept. 20, 1968 2Sheets-Sheet 1 l I l 9 RICHAR AMBROS HERMA ETTINGER F I G 2 INVENTOR.

ATTORNEY Aug. 4, 1970 os ET AL SLIDE-FASTENER SLIDER WITH LOCKING PAWLFiled Sept. 20, 1968 2 Sheets-Sheet 2 F l G .4

AMBRos ETTINGER INVENTOR.

RICHARD HERMANN ATTO'RNEY United States Patent 01 3,522,638 PatentedAug. 4, 1970 3,522,638 SLIDE-FASTENER SLIDER WITH LOCKING PAWL RichardAmbros, Nuremberg, and Hermann Ettinger, Erlangen, Germany, assignors toZipp Werk G.m.b.H., Nuremberg, Germany, a corporation of Germany FiledSept. 20, 1968, Ser. No. 761,092 Claims priority, application Germany,Sept. 20, 1967,

U.S. Cl. 24205.14 9 Claims ABSTRACT OF THE DISCLOSURE A slider for aslide-fastener stringer in which the upper shield member, which isjoined to the lower shield member by a wedge-shaped core, is providedwith a recess in which a rectangular locking pawl is disposed. A well inthe core receives a spring which bears against the locking pawl to urgethe latter against a camming eccentric of the handle flap to force atooth at the other end of the locking pawl into engagement with thecoupling elements through a window in the upper shield member. The flap,when swung about its pivot, cams the locking pawl against the springforce and about a fulcrum on the upper shield member to withdraw thetooth in the deadcenter position of the eccentric cam. Off thedeadcenter position, the spring retains the flap and the locking pawl intheir locking positions.

Our present invention relates to separable slide fasteners and, moreparticularly, to a locking slider for a slidefastener stringer.

Separable slide fasteners are currently in widespread use and,generally, comprise a slide-fastener stringer whose slider is shiftablealong a pair of interengageable coupling elements to interconnect andseparate in accordance with the direction of movement of the slider. Thecoupling elements, which can be continuous syntheticresin coils or achain of individual coupling members of synthetic resin or metal, aremounted upon respective support tapes so as to form slide-fastener headswhich, in turn, may be provided at the ends of the coupling elementswith so-called end-stop members designed to prevent the slider frombeing removed from the coupling elements.

The sliders of such devices usually include an upper and a lower shieldinterconnected by a core of Wedgeshaped configuration subdividing theinterior of the slider into a pair of channels which merge at the tailof the slider, i.e. at the trailing portion thereof with respect to thedirection of movement of the slider in the fastenerclosing direction.Such sliders are commonly provided with flaps, tongues, or other membersadapted to be gripped easily by the user for drawing the slider to andfro along the the stringer. It has also been a common practice toprovide such sliders with locking elements which engage between couplingheads of the coupling elements to prevent movement of the slider untilthe handle flap is lifted to release the locking arrangement. Such slidefasteners are often provided for trousers, shoes, corsets, and the like,inasmuch as they prevent the considerable lateral stress on the slidefastener from independently opening the system.

These locking devices have in the past included a lock ing pawlconstituting part of the handle flap and passing through a window oraperture in the upper shield member of the slider and engageable withone of the coupling elements when the handle flap is pushed toward theshield member. When the handle flap is lifted, the pawl or tooth iswithdrawn and the slider may be shifted. These units may also include aspring adapted to hold the handle flap ice and the pawl which is unitarytherewith in its locked position.

It has been found that these arrangements often have the disadvantagesthat the locking pawl is worn, bent or otherwise deformed or destroyed,thereby rendering the device ineffective. Replacement of the inefiectivepart is, of course, impossible in this conventional system. It may alsobe pointed out that clamping arrangements providing a friction lock forthe slider have proved to be unsatisfactory as well in practice.

It is an object of this invention to provide an improved slider forslide-fastener assemblies in which a firm lock is achieved with aminimum of eifort while the aforementioned disadvantages are avoided.

Another object of this invention is to provide a locking slider for aslide-fastener closure which is particularly resistant to opening and isthus highly desirable for shoes, trousers and corsets.

The slider of the present invention comprises, as is usual in suchstructures, an upper shield member and a lower shield member joinedtogether by a wedge-shaped core defining within the slider the mergingchannels through which the coupling elements pass. The present system,however, includes a locking pawl in the form of a tonguelike lever whichis structurally independent of the flap and is received in the uppershield member, While being spring-biased such that an inwardly benttooth of the pawl passes through a window or aperture in the uppershield member into engagement with the coupling elements upon which theslider is shiftable. Above this locking pawl there is provided a handleflap whose pivot is close to the locking pawl and which is formed withan eccentric cam held by the spring-biased locking pawl in the lockedposition of the device but swingable about this pivot to cam the lockingpawl against its biasing spring and withdraw the tongue from engagementwith the coupling element.

According to an important feature of this invention, the locking pawl isprovided with a pair of fulcra between the biasing spring which actsupon one end of the locking pawl and the tongue or tooth formed at theother end. One fulcrum is provided by the eccentric which has adeadcenter position in which the locking pawl is withdrawn fromengagement 'with the Icoupling element. On one side of this deadcenterposition, the spring urges the locking pawl against the cam which thenserves as the fulcrum and swings the pawl into engagement with thecoupling element. When the handle bap and cam are swung into or throughthe deadcenter position, the spring is overridden and the locking pawlis swung about the second fulcrum (formed on the upper shield memberbetween the first fulcrum and the locking tooth of the pawl) to bringthe locking pawl out of engagement with the coupling element.

According to a more specific feature of this invention, the upper shieldmember is provided with an outwardly open recess accommodating thegenerally flat locking pawl and at least partially enclosing the handleflap when the latter is in its locked position. Furthermore, we providea blind well in the upper shield member and the wedge-shaped core memberto accommodate a compression-type helical coil spring which bears uponan end of the pawl. Between this well or chamber and the window oraperture through which the locking tooth passes, we provide a secondfulcrum in the form of a ramplike surface extending from the springcompartment to a fulcrum edge disposed between the pivot of the handleand the window or aperture. The cam portion of the handle is thus ableto swing the locking pawl against the string in the region of the rampand above the second fulcrum. Furthermore, the handle flap may beremovably mounted in a pair of journal lu-gs which are bifurcated toallow slight spreading for insertion and removal of the handle flap.Upon removal of the handle flap, of course, the sheet-metal stampedlocking pawl, which is substantially flat and can be composed of springsteel, may be withdrawn and replaced. To this end, the locking pawl mayitself hav a window through which the journal lug passes and which isheld in place by the handle flap. It will be understood, however, that apair of such lugs may be provided and may cooperate with a central bossof the handle flap rather than a bifurcated structure.

The arrangement of the present invention has been found to be totallyunaffected by the problems which have plagued arrangements in which thepawl is mounted upon the handle flap, provides firm and positivelocking, and facilitates repair and replacement of the several parts.

The above and other objects, features and advantages of the presentinvention will become more readily apparent from the followingdescription, reference being made to the accompanying drawing in which:

FIG. 1 is a plan view of a slider according to the present invention;

FIG. 2 is a cross-sectional view taken along the line III I of FIG. 1;

FIG. 3 is a view similar to FIG. 2 with the parts thereof shown inanother operating position;

FIG. 4 is a sectional view, partly in elevation, with the handle flapand locking pawl removed from the slider embodying this invention; and

FIG. 5 is a cross-sectional view taken along the line V-V of FIG. 2.

In the drawing, we show a slider for a slider-fastener stringer of anyconventional type which comprises a lower shield member 1, an uppershield member 2 and a core 3 of wedge-shaped configuration (see FIG. 4)intenconnecting the upper and lower shield members and unitarily moldedfrom synthetic resin therewith.

The core member 3 defines within the slider a pair of channels 3a and 3b(FIG. 5) which merge at the trailing end 30 of the slider and have acollective width at the latter end which is less than the total of thewidth of the coupling elements so that the latter are interfitted asthey traverse the slider.

The upper shield member is provided with a generally flat locking pawl 4stamped from sheet metal and provided with a window 4a through which ajournal block or lug 13 of the upper shield member can pass. Therectangular locking pawl 4 is provided at its right-hand end (FIGS. 1, 2and 5) with a downwardly turned tooth 5, shown in FIGS. 2 and 5 in alocking position. The tooth 5 passes through a transverse aperture 1.1(FIGS. 2 and 4) in the upper shield member and projects downwardlybeneath the roof 2a of the channel within the slider to engage thecoupling elements which lie in these channels.

A handle flap 7 is formed with a bifurcated end 7a straddling the lug 13and is pivotally mounted therein by a pintle 7b bridging the cam-likeeccentric lugs 8 which bear upon the locking pawl 4.

A locking spring 6 (FIGS. 1 through 3) is received within a well 9 inthe upper shield member 2 and in the core 3 (see FIG. 4) and bearsupwardly against the lefthand end of the locking pawl 4. The latter thusconstitutes a lever with a fulcrum at 8a against the cam lug 8 wherebythe tooth 5 is urged in the clockwise sense through the aperture 11 andinto looking engagement with the coupling elements. Spring 6 is acompression-type helical coil spring which may be simply dropped intothe well 9.

Within a recess formed between a pair of protective ridges 10a and 10bof the upper shield member, the upper shield member 2 is provided with aramp 12 below the cam portions 8 and extending from the spring chamber 9to a fulcrum edge 12:: located between the fulcrum 8a and the tooth 5.The cams 8 are thus able to urge the left-hand end of the locking pawl 4in the counterclockwise direction sense about the edge 12a and therebyswing the tooth 5 out of engagement with the coupling elements.

The journal lug 13 is bifurcated, as will be apparent from FIGS. 1 and4, to allow the pintle 7b to be snapped out of the lug for mounting anddism'ounting of the Operating member 7. Furthermore, the generally flatlocking pawl 4, which is bent only to form the tooth 5, may be removedor replaced simply by withdrawing the operating flap 7 and positioningthe original or another locking pawl over the lug 13.

We claim:

1. A locking slider for a slide-fastener stringer having a pair ofcoupling elements adapted to pass through said slider for connection anddisconnection of the coupling elements upon movement of the slider inopposite directions therealong, said slider comprising a slider bodyformed with an upper shield member, a lower shield member and a coremember interconnecting said shield members and defining therewith a pairof channels for said coupling elements said body being provided with awell open at said upper shield member in the region of said core member;a generally flat elongated locking pawl on said upper shield memberformed at one end remote from said well with a tooth for engagement withat least one of the coupling elements in said slider, thereby lookingsaid slider thereto, said locking pawl overlying said well at its otherend; a compression coil spring bearing upon said other end of said pawland received in said well; and a handle flap pivotally mounted on saidupper shield member and provided with an eccentric cam swingable aboutits pivot axis and engageable with said locking pawl intermediate saidwell and said tooth and adapted to displace said locking pawl againstthe force of said spring to withdraw said tooth from. engagement withthe coupling elements, said upper shield member being formed with afulcrum for said pawl between said camming formation and said tooth.

2. A slider as defined in claim 1 wherein said upper shield member isformed with at least one journal lug pivotally supporting said flap,said spring urging said locking pawl against said cam to swing thelocking pawl into engagement with the coupling elements, said other endof said pawl retaining said spring in said well.

3. A slider as defined in claim 2 wherein said upper shield member isprovided with an aperture proximal to said one end of said locking pawl,said tooth extending through said aperture in a position of said pawlgenerally fiat against said upper shield member, said pawl being formedwith a window receiving said lug, said flap being bifurcated and lyingon opposite sides of said lug while bearing upon said pawl on saidopposite sides, said upper shield member being formed with a generallyflat ramp extending from said fulcrum to said well, said pawl restingagainst said ramp upon pivotal movement of said flap to swing said pawlabout said fulcrum and withdraw said tooth from said coupling elements.

4. A locking slider for a slide-fastener stringer having a pair ofcoupling elements adapted to pass through said slider for connection anddisconnection of the coupling elements upon movement of the slider inopposite directions therealong, said slider comprising a slider bodyformed with an upper shield member, a lower shield memher and a coremember interconnecting said shield members and defining therewith a pairof channels for said coupling elements; a locking pawl on said uppershield member formed at one end with a tooth and spring biased into theinterior of said slider for engagement with at least one of the couplingelements therein, thereby looking said slider thereto; and a handle flappivotally mounted on said upper shield member and provided with acamming formation adapted to displace said locking pawl against itsspring bias and withdraw said tooth from engagement with the couplingelements, said upper shield member being formed with at least onejournal lug pivotally supporting said flap, said flap being providedwith an accentric cam swingable about its pivot axis and engageable withsaid locking pawl, the spring bias of said locking pawl urging sameagainst said cam to swing the locking pawl into engagement with thecoupling elements, said upper shield member being provided with anaperture proximal to said one end of said locking pawl, said toothextending into said aperture, said slider further comprising acompression-type spring bearing upon an opposite end of said lookingpawl and urging same against said cam, said cam bearing upon saidlocking pawl intermediate said ends, said upper shield member defining afulcrum for said locking pawl intermediate said cam and said one of saidends whereby swinging movement of said flap and said cam pivot saidlocking pawl about said fulcrum to withdraw said tooth from engagementwith the coupling elements, said cam having a deadcenter position inwhich said locking pawl is swung out of engagement with said couplingelements, said spring retaining said flap in an oif-dcadcenter positionupon locking engagement of said pawl with the coupling elements, saidupper shield member being provided with a ramp inclined from said secondfulcrum to said well away from said cam and therebelow whereby said camretains said pawl against said ramp in said deadcenter position.

5. A slider as defined in claim 4 wherein said upper shield member isprovided with an upwardly open well extending into said core member andreceiving said spring.

6. A slider as defined in claim 4 wherein said upper shield member isformed with a recess receiving said locking pawl.

7. A slider as defined in claim 4 wherein said bearing lug is bifurcatedto facilitate insertion and removal of said flap, said flap beingbifurcated and extending on opposite sides of said lug while beingprovided with cam formations on opposite sides thereof.

8. A slider as defined in claim 7 wherein said locking pawl is generallyrectangular and is stamped from sheet metal, said locking pawl beingsubstantially flat except for the region of said tooth and being formedwith a window, said lug projecting through said window, said well andsaid aperture being formed within said recess.

9. A locking slider for a slide-fastener stringer having a pair ofcoupling elements adapted to pass through said slider for connection anddisconnection of the coupling elements upon movement of the slider inopposite directions therealong, said slider comprising:

a slider body formed with an upper shield and a lower shield defining apair of channels for said coupling elements;

a generally fiat elongated locking pawl overlying said upper shield andformed at one end and with a downwardly turned tpoth, said body beingformed with a well extending transversely to said locking pawl beneaththe other end thereof and overlain by said other end of said' lockingpawl;

a coil spring received in said well and bearing upon said other end ofsaid locking pawl to bias same away from said upp r. shield;

a pivot lock formed on said upper shield and protruding through saidloigking pawl, said locking pawl being formed with a window passing:said lug; and

a handle flap having a bifurcated end pivotally mounted on said lugandjflanking same, said flap being formed on opposite sides of said lugwith eccentric camming formations engaging said locking pawl betweensaid spring and said tooth and along a side of said locking pawlopposite said spring, said upper shield being formed with a fulcrumbetween said camming formations and said tooth enabling pivotingmovement of said locking ,pawl under the control of said flap, saidupper shield; being further provided with a recess formed with a rfampbetween said well and said fulcrum and beneath said camming formationswhereby said locking pagwl is pressed against said ramp upon swingingmovement of said flap.

ihferences Cited UNITED STATES PATENTS 2,289,955 7/1942 Berg 24--2( 5.14

2,397,693 4/ 1946 Rabinow 24-20514 2,487,3 86 11/ 1949 Scheuermann24205. 14

2,520,496 8/ 1950 Deutsch 24--205.14

3,270,535 9/ 1966 Fukuroi 24-20514 FOREIGN PATENTS 1,078,005 11/ 1954'France.

BERNARD A. GELAK, Primary Examiner

